Subspecies of Blue Grosbeak and its potential use for Motus tags

This is an evaluation of the sub-species of Blue Grosbeak (Passerina caerulea) and its potential use as model species for Oaxacan Central Valleys. Most information comes from Birds Of the World https://birdsoftheworld.org/bow/species/blugrb1/cur/introduction and the publication from Storer and Zimmerman (1959) https://deepblue.lib.umich.edu/items/24824b17-6f43-4b56-9ad8-64da66786885.

Currently, 6 sub-species have been recognized, their infromation about morphometrics and distribution is summarized on this table:

Sub especie Region Breeding Wintering Wing length mean (mm) Wing length range Tail length mean Tail length range Culmen length mean Culmen length range Body mass mean Body mas range
caerulea Eastern North America Nebraska, Pensilvania, Texas, South Carolina Greater antilles, E & S México, Panama 88.36000 85 - 92 66.75333 63-73.5 12.44333 11.3 - 13.7 NA NA
interfusa Western North America and México Nevada, Colorado, Sonora, Chihuahua Sonora, Jalisco and Valley of México 89.70667 86.5 - 94 69.58667 66 - 75 12.24000 11.1 - 14 NA NA
salicaria Californias California and Baja California Baja California Sur 90.35000 88 - 94 71.00000 68 - 74.5 11.16000 10 - 11.8 NA NA
eurhyncha México México, Guanajuato, SLP, Northern? Oaxaca NA 94.17400 90 - 96 74.37000 70 - 80 12.94800 12.1 - 13.7 NA NA
eurhyncha Oaxaca (n = 2) Oaxaca (9 and 20mi Southeast Oaxaca) NA 95.50000 95-96 75.00000 74 - 76 13.30000 12.9 - 13.7 NA NA
chiapanensis Chiapas (n = 7) Chiapas NA 95.90000 93.5 - 98.5 76.60000 73 - 81 14.80000 14.5 - 15.1 NA NA
lazula Central America El Salvador, Costa Rica NA 91.11000 87.5 - 93 73.33000 68.5 - 77 14.09000 12.7 - 15.1 NA NA

From these species, 2 or maybe 3 could be found in Oaxaca. These are caerulea, interfusa and eurhyncha.

Sub especie Region Breeding Wintering Wing length mean (mm) Wing length range Tail length mean Tail length range Culmen length mean Culmen length range Body mass mean Body mas range
caerulea Eastern North America Nebraska, Pensilvania, Texas, South Carolina Greater antilles, E & S México, Panama 88.36000 85 - 92 66.75333 63-73.5 12.44333 11.3 - 13.7 NA NA
interfusa Western North America and México Nevada, Colorado, Sonora, Chihuahua Sonora, Jalisco and Valley of México 89.70667 86.5 - 94 69.58667 66 - 75 12.24000 11.1 - 14 NA NA
eurhyncha México México, Guanajuato, SLP, Northern? Oaxaca NA 94.17400 90 - 96 74.37000 70 - 80 12.94800 12.1 - 13.7 NA NA
eurhyncha Oaxaca (n = 2) Oaxaca (9 and 20mi Southeast Oaxaca) NA 95.50000 95-96 75.00000 74 - 76 13.30000 12.9 - 13.7 NA NA

Based on measurements we could tell appart individuals(?)

But the distribution of interfusa and eurhyncha for Oaxacan Central Valleys do not seem to overlap…

What does ebird say?

Blue Grosbeaks in Oaxaca

To evaluate the status and trends in detail I requested a status and trends passcode

“Tu clave de estatus y tendencias:

4inq4qjs1326”

BLUE GROSBEAKS AUDIOS

Here is information from the Macaulay library. I selected audios from each locality between June and August. All songs selected include at least 2 trill elements

NOTE: subspecie caerulea and and interfusa had longer songs than eurhyncha but were not included in these comparisons

The information of the audios goes as follows:

Oaxaca (eurhyncha)

Resident

ML640535448.
ML640535448.

ML622186110 ML255479461

ML636797365
ML636797365

NEW MEX, COLORADO(interfusa)

West Migrant

ML550323781
ML550323781
ML562328101
ML562328101
ML67756551
ML67756551
ML465652321
ML465652321

PEN, SOUTH CAROLINA (caerulea)

East migrant

ML621600823
ML621600823
ML621003816
ML621003816
ML248063861
ML248063861
ML350040061
ML350040061